Police are looking for a 17-year-old woman who disappeared from her Staten Island home with her 6-week-old daughter on Friday.

Tierra Vance left with $40, underwear for herself, and pajamas for the infant – no formula, no warm clothing, and none of the psychiatric medication she was taking to treat various debilitating mental illnesses, Ms. Vance’s legal guardian, Blanca Torres, 38, said.

Ms. Vance had been living with Ms. Torres and her three biological children on Nicholas Street in St. George since March, Ms. Torres said. Ms. Vance, her siblings, and their mother lived in a housing development in the West 60s in Manhattan until early this year, where Ms. Vance met her boyfriend, Julio Perez, also 17, Ms. Torres said.

Ms. Vance’s mother decided to move the family to Brandon, Fla., near Tampa, in January. Ms. Vance’s mother “wanted to have a new life,” Ms. Torres said. Ms. Vance’s mother did not respond to two telephone calls requesting an interview. That month, Ms. Vance learned she was pregnant with her boyfriend’s child. In March, Ms. Vance’s boyfriend and his mother gave Ms. Vance money to run away and come back to New York City. Contact information for Mr. Perez and his mother was not available. Ms. Vance was unwilling to return to Florida and Ms. Torres became her legal guardian that month.

During the course of her pregnancy, Ms. Vance started hearing voices, Ms. Torres said, that told her to kill herself, as well as her unborn child. The depression became so severe that Ms. Vance was admitted to a hospital for psychiatric care as an inpatient.

Ms. Vance was on a 45-day leave from 10th grade at Curtis High School to care for her baby until November 1. Once the child, Aleysha Perez, was born, Ms. Vance started taking Cymbalta – a drug for treatment of a major depressive disorder that is not approved by the FDA for use in patients under the age of 18 – which Ms. Torres said quieted the voices in her niece’s head. Ms. Vance was under the treatment of a psychiatrist and a therapist at Staten Island Mental Health Society. Despite taking the medication, “as time went on, she was getting more depressed,” Ms. Torres said.

As recently as last week, the staff at Staten Island Mental Health thought Ms. Vance may have started hearing voices again, although Ms. Vance denied it, Ms. Torres said. Ms. Vance allegedly could not get out of the bed or care for Aleysha as the paranoia was setting in.

Ms. Torres last saw Ms. Vance at 11a.m. on Friday morning when Ms. Torres left for work. On Friday, at about 12:15 p.m., Ms. Torres’s son got home to find that Ms. Vance and the baby were missing. That night at 8:30 p.m., Ms. Vance called Ms. Torres and spoke to a neighbor who was in the house while Ms. Torres was filing a missing person’s report. Ms. Vance asked the neighbor to tell her legal guardian that she was “okay.” Since then, Ms. Torres said, “There’s been no contact whatsoever with anyone.”

Police are asking anyone with information on the whereabouts of Ms. Vance and her daughter to call CrimeStoppers at 800-577-TIPS.